The objective of this proposed project is to understand the molecular mechanism(s) whereby calcium exerts its effects on and regulates cell processes. Calcium exerts its biological effects via interaction with calcium modulated proteins. Modulator protein, a calcium modulated protein, regulates in a calcium dependent manner a number of enzyme activities. This suggests that modulator protein may be a pleiotropic regulator of metabolic and mechanochemical processes in the cell. Modulator protein isolated from chicken fibroblasts, brain and gizzard will be compared to modulator protein from human brain and tumor tissue and to modulator protein from bovine brain, whose complete amino acid sequence has been determined. Modulator associated proteins will be isolated using a combination of affinity chromatography and classical protein chemistry methodologies. Modulator protein and modulator associated proteins will be localized in normal and virus-transformed fibroblasts. The isolation, characterization and subcellular localization of a calcium modulated protein and of the enzymes which it regulates will contribute to our knowledge of how calcium regulates normal cell processes and might provide new insights into the molecular mechanism(s) of cell transformation.